So, it goes like this:

Poster: cat
Postee: care
Poster: cage
Poster: page

And etc. If you get stumped, you can repeat the previous word! I'll start:

hug

huge

luge

Lupe

Lung

Long

Log

Lag

Leg

Beg

Bag

Tag

Tall

Mall

Small

Smell

Semel

Aemel.